Species introduced to Scotland

While many familiar mammals such as rabbits, mice and rats may appear to be native British animals, they have actually been introduced, either accidentally or deliberately. Brown rats appeared as late as 1730, the Grey Squirrel in 1870, and although the rabbit was introduced by the Normans, it did not reach some areas of the Highlands of Scotland until the 19 th century: Some of those Highlanders who marched with Bonnie Prince Charlie in 1745 might have seen a wolf, but never set eyes on a rabbit.

Some of the introduced species, such as the Musk Rat and the Hog Deer, became extinct, either because they could not adapt to the environmental conditions or because of a campaign of extinction. Others like the grey squirrel and the Fallow deer extablished themselves as successful wild populations are now considered to be natives. On this basis there are those who claim that big cats have now integrated into the British ecosystem and are no longer aliens.

Some of the introductions were deliberate. There was a Victorian soorganisation called the "Acclimatisation Society", which was essentially wealthy landowners and amateur scientists seeking to introduce new species to the UK - largely for hunting purposes but also for control of existing wildlife. The society was responsible for the introduction of the Grey Squirrel. Many of the founder members were ex-officers from the Indian army and would conceivably have hunted tiger & leopard in India. Given the wish to improve hunting in UK, could they possibly have introduced big cats into the UK?

Recent genetic studies have shown that native British species are at threat from dilution of their genes by introduced species. The Scottish wildcat, Felis silvestris grampia has hybridised with feral domestic cats Felis catus. The famous Kellas Cats of the Highlands are thought by many to be an example of such a hybrid. Several years ago, a gamekeeper avoided prosecution for shooting a wildcat, a protected species, as the prosecution was unable to prove that the cat was not a hybrid. This case has left the Scottish wildcat, of which there are only an estimated 3,500 individuals left, completely without legal protection. For other species, drastic measures have been proposed. In the case of the Sika deer, which has been hybridising with native red deer, the Scottish Deer Commission has proposed to eradicate the introduced species from Scotland.

Introduction of non-native species

Scottish Natural Hertiage's report for 1998 lists sixteen non-native species of mammals which have been introduced to Scotland. These are:

Species introduced into Scotland

Species

Latin name

Year introduced

Estimated number

% of British population

Feral sheep

Ovis aries

?

1,850

88 %

Brown hare

Lepus europaeus

?

187,250

23 %

Harvest mouse

Micromys minutus

?

0?

0 %

Feral ferret

Mustela furo

?

2,500

95 %

Feral goat

Capra hircus

? 4000 bp

2,650

74 %

Feral cat

Felis catus

Roman times

130,000

16 %

Fallow deer

Dama dama

Roman times

4,000

4 %

House mouse

Mus domesticus

Roman times

657,000

13 %

Rabbit

Oryctolagus cuniculus

12 th century

8,000,000

21 %

Ship (black) rat

Rattus rattus

12 th century

50

6 %

Common (brown) rat

Rattus norvegicus

1730

870,000

13 %

Orkney vole (Common vole)

Microtus arvalis

1805

1,000,000

100 %

Grey Squirrel

Sciurus carolinensis

1890

200,000

8 %

Sika deer

Cervus nippon

1900

9,000

78 %

Reeves Muntjac1

Muntiacus reevesi

after 1900

0?

0 %

Red necked wallaby (Bennett's wallaby)

Macropus rufogriseus

1940s

28

90 %2

American mink

Mustela vison

1950

52,250

48 %

1Muntjac are not listed amongst the introduced species, but the offical report states that there were sightings in 1994.2It is common knowledge, (except to the MAFF), that there is a colony of 200 or so Red-necked wallabies in Debyshire which have been breeding since they escaped in the 1940s. The Scottish figure is estimated to be around 10 % of the British population.

Felids

Note the absence of any 'alien big cat' from the above table. The government does not accept that there is any conclusive evidence that wild felids (apart from Scottish wildcats, feral cats and hybrids) are at large in Scotland despite the fact that there have been over 1,000 reports to the police of sightings of big cats in the past 20 years.

However, it is interesting to note that the government's own report explains the apparent absence of frogs in certain regions of Scotland by stating 'Other apparent absences, at least from mainland Scotland, are probably the result of a lack of records rather than a real absence of frogs, except in the very highest mountainous areas.'